The effects of chemical injury on the ocular surface

Chemical burns of the eye may destroy all of the corneal epithelium and large portions of conjunctival epithelium into the fornices. Restoration of the ocular surface after a chemical burn depends on the centritedal movement of conjunctival epithelial cells and their adherence to the altered corneal stroma. Epithelial movement after a corneal burn is normal for 72 hours after a burn, but persistent epithelial defects thereafter commonly are not resolved until total corneal vascularization occurs. Although this fresh epithelium may be protected by a bandage soft contact lens, more promising and far-reaching approaches may follow epithelial supplementation and even replacement. The link between the health and integrity of the epithelial layer as it relates to the corneal substratum and its cellular constituents remains to be forged.     

Lipolytic sensitivity and response to fasting in normotensive and hypertensive obese humans

Obese persons with hypertension are at greater risk for diabetes and hyperlipidemia than normotensive obese persons. It has been postulated that increased lipolytic rates contribute to these metabolic diseases. Therefore, we evaluated the glycerol rate of appearance (Ra) in plasma, an index of whole-body lipolytic activity, during basal conditions and during 60 minutes of epinephrine infusion after 12 and 84 hours of fasting in six normotensive (body mass index [BMI], 39.9 +/- 1.8 kg/m2) and six hypertensive (BMI, 38.7 +/- 1.6 kg/m2) obese persons. Basal glycerol Ra was lower in hypertensive than in normotensive subjects at both 12 hours (1.58 +/- 0.21 v 2.27 +/- 0.28 mumol/kg/min, respectively; P < .01) and 84 hours (2.04 +/- 0.06 v 2.50 +/- 0.13 mumol/kg/min, respectively; P < .01) of fasting. Peak glycerol Ra during epinephrine infusion after 84 hours of fasting (5.69 +/- 0.72 and 11.40 +/- 0.78 mumol/kg/min for hypertensive and normotensive subjects, respectively) was significantly greater than at 12 hours (3.09 +/- 0.29 and 5.06 +/- 0.69 mumol/kg/min) in both hypertensive and normotensive subjects. However, peak glycerol Ra was lower in hypertensive than in normotensive subjects after 12 and 84 hours of fasting (P < .01 for 84 hours). We conclude that hypertension in obese persons is associated with a decrease in both basal lipolytic rates and lipolytic sensitivity to epinephrine infusion.